The present invention relates to a dummy pin, particularly to a dummy pin that is inserted into a terminal insertion port into which a terminal is not inserted among a plurality of terminal insertion ports of a waterproof connector.
Conventionally, there is known a waterproof connector in which a seal member having a plurality of seal holes corresponding to a plurality of terminal insertion ports formed at a housing is attached to the housing so that terminals are to be inserted from the terminal insertion ports of the housing into the corresponding terminal accommodating portions in the housing through the seal holes of the seal member.
In a waterproof connector of this type, when a terminal insertion port into which no terminal is inserted is present among the plurality of terminal insertion ports, it is necessary to fill the terminal insertion port into which no terminal is inserted in order to prevent water intrusion into the waterproof connector.
To cope with it, for example, JP 2004-71200 A discloses a dummy pin 1 made of resin for filling a terminal insertion port as shown in FIG. 15. The dummy pin 1 has a cylindrical seal portion 3 projecting forward from a rectangular parallelepiped main body 2, hook portions 4 respectively projecting on an upper surface and a lower surface of the main body 2, and a flange portion 5 formed at a rear portion of the main body 2.
As shown in FIG. 16, a waterproof connector 6 has a structure that a seal member 8 is disposed in a concave portion 7B communicating with a terminal accommodating portion 7A of a housing 7 and a cover 9 is attached to a rear end of the housing 7. When the dummy pin 1 is inserted into a terminal insertion port 9A formed in the cover 9, the seal portion 3 of the dummy pin 1 is fitted into a seal hole 8A of the seal member 8, which prevents water intrusion to the terminal accommodating portion 7A.
Further, when the dummy pin 1 is firmly pushed into the waterproof connector 6, the hook portions 4 of the dummy pin 1 go over projections 9B respectively projecting on an upper edge and a lower edge of the terminal insertion port 9A of the cover 9 and accordingly, the projections 9B are positioned between the hook portions 4 and the flange portion 5 of the dummy pin 1, which prevents the dummy pin 1 from falling off the waterproof connector 6.
However, since the dummy pin 1 disclosed by JP 2004-71200 A is prevented from falling off by making the hook portions 4 respectively projecting on the upper surface and the lower surface of the main body 2 catch on the projections 9B respectively projecting on the upper edge and the lower edge of the terminal insertion port 9A of the cover 9, the dummy pin 1 cannot be inserted into the waterproof connector 6 in a normal manner unless the hook portions 4 project in the particular direction, i.e., the vertical direction.
Further, there is a problem in that the structure of the waterproof connector 6 becomes complicated since in order to prevent the dummy pin 1 from falling off, it is necessary not only to form the hook portions 4 projecting on the dummy pin 1 but also to form the projections 9B projecting on the upper edge and the lower edge of the terminal insertion port 9A of the cover 9 which is a component of the waterproof connector 6.
Further, in order to mold resin into the dummy pin 1 having the structure that the hook portions 4 respectively project on the upper surface and the lower surface of the main body 2 as shown in FIG. 15, it is necessary to use a metal mold that is divided in a direction perpendicular to a central axis along which the seal portion 3 of the dummy pin 1 extends to take out the dummy pin 1 from the metal mold after molding.
Therefore, due to the divided surface of the metal mold, a parting line along the central axis direction is generated on an outer peripheral surface of the seal portion 3 after molding, whereby the outer peripheral surface of the seal portion 3 cannot form a continuous surface over the whole circumference thereof. Since the parting line causes formation of projections, bumps and the like, even if the dummy pin 1 as above is inserted into the waterproof connector 6, tight contact between an inner surface of the seal hole 8A of the seal member 8 and the seal portion 3 of the dummy pin 1 in the waterproof connector 6 becomes insufficient, which may degrade waterproof properties.